Synthesis and characteristics of pectiniform polyurethane‐modified polycarboxylate at room temperature

Abstract

In this article, modified polyurethane prepolymer was synthesized by segmental synthesis method using isophorone diisocyanate, hydroxyl‐terminated silicone, polyether glycol dimethylolpropionic acid as raw materials. After that, pectiniform polycarboxylate, of which side chains were in roughly the same polymerization degree and main chains were in different lengths, was synthesized at room temperature in initiation system of hydrogen peroxide, ascorbic acid, and persulfate. Moreover, influence of various factors on the synthesis of polyurethane‐modified polycarboxylate at room temperature was discussed in detail and optimal synthesis process was determined. Results showed that redox initiation system, increasing initiator and monomer concentration, and extending reaction time needed to be adopted to complete the reaction. However, when the reaction time was over 4 h, water reducing of polycarboxylate declined rapidly. In addition, it could be found in Fourier transform infrared spectrum analysis that the CC double bonds in acrylic acid were opened and polymerized, macromolecular chain segments were successfully connected to polyoxyethylene chain segment, and resulting polycarboxylic acid molecule contained hydroxy, carboxyl, methyl, ester group, and other groups. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45873.

Influence of a polyurethane‐modified polycarboxylate on properties of cement mortar

“…The synthesis reaction formula and the designed side chain molecular structure were shown in Figure 3 10 . In synthesis, alcohol and amine compounds with low molecular weight polyfunctional groups containing hydroxyl or amino groups were introduced in the main chain of PCE molecules to increase the number of short branches, promote alternate distribution of polyether long branches and branched short chains of the chain extender of alcohol and amine compounds, thereby increasing dispersibility and adaptability of the water reducing agent.…”

“…The following was a basic formula for synthesis of M‐PCE at room temperature: with Step 2.2, a solution containing 120 g TPEG (0.05 mol), 81 g deionized water(4.5 mol), and 10 g PEG‐200 (0.05 mol) was fully stirred in a 250 ml four‐neck round‐bottom flask 10 . Another solution containing 0.1 g dibutyltin dilaurate (0.00015 mol), 0.86 g toluene sulphonic acid (0.005 mol), and 3.4 g 30% H 2 O 2 was added (0.03 mol).…”